TypeScript Microsoft

TypeScript 2.0 is nearing two-years-old after Microsoft debuted it during September of 2016. The open source JavaScript subset is due a major release bump, even though Microsoft has been updating 2.0 in the interim period. Now, the company has introduced TypeScript 3.0.

Again, Microsoft has not been ignoring the service. This is a major update leap from 2.0 to 3.0, but the actual bump is from TypeScript version 2.8 to TypeScript version 3.0.

The most significant changes in this release include the “unknown” becoming a type. This means unknown can now longer be used for type declarations and is now a specific reserved type.

As usual with a major version release, numerous API breaking changes. Microsoft says many of the changes are to accommodate methods that have been removed or internalized. You can check out the full changelog for TypeScript 3.0 below:

  • Project references
    • –build mode
    • Controlling output structure
  • Extracting and spreading parameter lists with tuples
  • Richer tuple types
  • The unknown type
  • Improved errors and UX
    • Related error spans
    • Improved messages and elaboration
  • Support for defaultProps in JSX
  • /// directives
  • Editor Productivity
    • Named import refactorings​
    • Closing JSX tag completions and outlining spans
    • Quick fixes for unreachable code and unused labels

Availability

Users wanting the new TypeScript experience can get it by adding this command into Node Package Manager:

npm install -g typescript

Microsoft has made editor support available in Visual Studio 2015 and 2017. Visual Studio Code and Sublime Text 3 also support the new TypeScript. Microsoft says the JavaScript will become available in other editors in the future.